SUSCEPTIBILITY OF MONOSPECIES AND DUAL-SPECIES BIOFILMS OF STAPHYLOCOCCUS AUREUS AND ESCHERICHIA COLI TO ESSENTIAL OILS

The aim of this study was to investigate the susceptibility of Staphylococcus aureus and Escherichia coli biofilms formed on the polypropylene surface. The cultures were developed for 240 h, planktonic growth was characterized by colony-forming unit (cfu)/mL and biofilms was characterized by quantifying biomass and cfu/cm2. Essential oils (EOs) of citronella and lemon were extracted by hydrodistillation and characterized by gas chromatography. Biofilm formation occured after 3 h of contact. In dual-species biofilms, there was competition; S. aureus was the number of viable cells damaged by E. coli (P < 0.05). The EOs disinfectant action was similar in biofilms monospecies, viable cells and biomass decreased significantly. Dual-species biofilms were more resistant to EOs. The action EOs on biofilm suggest promising alternatives to sanitize industrial polypropylene surfaces. PRACTICAL APPLICATIONS Historically, the majority of new drugs has been generated from natural products (secondary metabolites) and from compounds derived from natural products. The extracts of higher plants have been and still are widely used to obtain substances with antimicrobial action. However, their low concentration in the extract often makes the purification processes or the synergistic action of the different compounds unfeasible, causing major problems for industries. Seeking to reduce the parameters involved in the isolation and purification of compounds, these essential oils (EOs) have been studied. They present high antimicrobial efficiency, and in appropriate concentrations they are considered safe. The antimicrobial activity of EOs was showed that such substances can be used with sanitizing agents in industrial surfaces against bacterial biofilms. However, this line of research is still very new, so it is important to continue research for the development of industrial sanitizing with EOs.